Diesel Kiki Co., Ltd.

Zexel Gmbh

Takayuki Ikeda

Takeo Kushida

Hideya Kikuchi

Nobuo Aoki

Fujio Aoki

Tomoharu Sato

Koichiro Futamase

Katsuhiko Tsukazaki

Ken Sato

Hisashi Nakamura

Satoshi Takahashi

Toshiaki Asami

Masaaki Ogino

Tomie Kobayashi

Toru Mogi

A pump for low-viscosity fuel comprises a pump shaft 6 installed in a pump housing 2, 3, 4 and divided into a drive-side shaft 6A and a driven-side shaft 6B, a partition 12 provided between the drive-side shaft and the driven-side shaft of the pump shaft to prevent leakage of fuel from the housing, and a magnetic coupling 13 for transferring torque from the drive-side shaft to the driven-side shaft of the pump shaft through the partition, the magnetic coupling being disposed such that a first clearance C1, D1 between the magnetic coupling and the partition is larger than a second clearance C2, D2 between the magnetic coupling and the pump housing. When wobble occurs in the pump shaft owing to wear of the sliding contact portions thereof, the magnetic coupling makes contact with the pump housing before contacting the partition, thereby enabling the rotation of the pump shaft to be stopped before fuel leakage occurs.

Clearance means to prevent fuel leakage in a radial piston pump

A radial piston pump for low-viscosity fuel according to a first aspect of the invention comprises a pump housing, which is constituted of as few as two structural bodies (from among a drive-side housing member 2A, a fixed cylinder 81 and a cover 4), and a leaf valve member 82 which is formed with intake valves 87 for opening and closing intake side passages 27 and discharge valves 88 for opening and closing discharge side passages 28 and is sandwiched between two structural bodies (fixed cylinder 81 and cover 4). The first aspect of the invention reduces the number of components constituting the pump housing, enables highly precise overall axial alignment, prevents wobbling of a pump shaft 9 of the pump, increases performance and reliability and reduces cost. A radial piston pump for low-viscosity fuel according to a second aspect of the invention comprises a leaf valve member 205 formed in one and the same plane thereof with overflow ports communicating with an overflow passage 59 in the pump housing, intake valves 87 communicating with intake side passages 27 and discharge valves 88 communicating with discharge side passages 28. The third aspect of the invention provides a method for assembling the radial piston pump for low-viscosity fuel according to the second aspect of the invention.

Radial piston pump for low-viscosity fuel

A pressure equalizer valve device incorporated in a fuel delivery valve assembly for use in a fuel injection pump, the fuel delivery valve assembly having a valve chamber and a delivery valve member axially movable in part within the valve chamber, the pressure equalizer valve device including a hollow equalizer valve casing member secured to the delivery valve member and having a valve seat surface portion, an equalizer valve element movable into and out of a position seated on the valve seat surface portion, a spring seat member engaging the equalizer valve element, and a helical compression spring seated at one end on the spring seat member and at the other within the delivery valve member, wherein the equalizer valve element, the spring seat member and the spring are all accommodated within the equalizer valve casing member.

Pressure equalizer valve device of fuel injection pump

A two-way delivery valve structure of a fuel discharge valve in a fuel injection pump has a valve holder formed in an interior part thereof with an oil chamber communicating with a fuel injection pipe, a valve seat secured in the holder and formed in an interior part thereof with a fuel outlet conduit communicating with a pressure chamber, an discharge valve communicating with the pressure chamber and for engaging with and disengaging from an opening of the fuel outlet conduit so as to open and close the conduit, and a two-way delivery valve mounted to the fuel discharge valve and provided in an interior part thereof with a valve chest communicating with the fuel discharge valve, the two-way delivery valve being provided in the valve chest with a movable valve comprising a check valve for opening and closing a communicating portion communicating with the oil chamber, a valve casing constituting the two-way delivery valve being provided separately from the fuel discharge valve, the valve casing and fuel discharge valve being integrally assembled through engaging reference surfaces thereof.

Two-way delivery valve structure of a fuel discharge valve in a fuel

Growing community of inventors

Higashimatsuyama, Japan

Takayuki Ikeda